European Patent Application EP 0 955 687 A2 discloses a method for preparing a slurry for forming a catalyst layer of a PEM fuel cell electrode. In the disclosed method, MOH is added to a water/alcohol solution of a perfluorosulfonate ionomer (PFSI) (such as Nafion™) to convert the PFSI to M+ form. An organic polar solvent such as dimethyl sulfoxide, N,N-dimethyl formamide or ethylene glycol is added ('687 at para. 24, para. 27, and claim 6). The mixture is then heated to drive off alcohol and catalyst is added to form the slurry. After the slurry has been applied to a backing layer and dried to form a catalyst layer, the catalyst layer is treated with acid to convert the PFSI from M+ form to H+ form. ('687 at para. 44 and claim 5).
U.S. Patent Application Publication US2002/0045081 discloses the use of sulfonated PEEK polymers dissolved in N-methyl pyrrolidone (NMP), a polar aprotic solvent ('081 at Example 1).
U.S. Pat. No. 5,906,716 discloses a metalized cation exchange membrane preferably made with a cation-exchange polymer that is soluble in a polar aprotic solvent (such as NMP) and comprises arylene units in the backbone of the polymer, e.g., sulfonated PEEK polymers ('716 at Example 1).
U.S. Patent Application Publication US2002/0019308 discloses a composite catalyst.
Japanese Unexamined Patent Publication 2000-353528 discloses a porous electrode catalyst layer and a method of making a porous electrode catalyst layer. The Examples appear to disclose the use of a solution of Nafion™ in NMP, obtained by solvent exchange of a stock solution of Nafion™.
Japanese Unexamined Patent Publication 2001-273907A discloses a porous electrode catalyst layer and a phase separation method of making a porous electrode catalyst layer. The Examples appear to disclose the application of suspension of catalyst in Nafion™ solution followed by drying and then application of a PVdF/NMP solution followed by solvent exchange with water to create a porous layer of PVdF.
International Patent Application WO 01/71835 A2 discloses a method of manufacturing a membrane/electrode composite.
UK Patent Application GB 2 316 802 A discloses gas diffusion electrodes based on polyethersulfone carbon blends.
U.S. Pat. No. 5,716,437 discloses an aqueous ink for use in electrode manufacture.
WO 99/21239 discloses a method for the production of metal colloid solutions by reducing dissolved catalyst metals in the presence of a cation exchange polymer.